cities_information={
    'Nanjing':{'nation':'China','population':'1w','fact':'NB'},
    'NewYork':{'nation':'American','population':'10w','fact':'modern'},
    'London':{'nation':'England','population':'30w','fact':'pollution'},
}
for city,information in cities_information.items():
    print(f"The {city} has the following information:")
    for key,value in information.items():
        print(f"\t{key}:{value}")
    